Pronunciation: (pep'sin), [key]
1. an enzyme, produced in the stomach, that in the presence of hydrochloric acid splits proteins into proteoses and peptones.
2. a commercial form of this substance, obtained from the stomachs of hogs, used as a digestive, as a ferment in the manufacture of cheese, etc. Also,pep'sine.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.